Lifting jack



Dec. 31, 1929. w. HJSTONE LIFTING JACK Filed April 26, 1927 5 Sheets-Sheet l Dec. 31, 1929. w. H. STONE LIFTING JACK 6 Sheets-Sheet 2 Filed April 26, 1927 w. H. STONE LIFTING JACK Dec. 31, 192!} Filed April 26. 1927 3 Sheets-Sheet 5 4' W f 1m E J im;

m HI m' llll "III v l I Patented Dec. 31, 1929 UNITED BATES WILLIAM H. STONE, OF GOODLAND, KANSAS LIFTING' JACK Application filed April 26,

l provision of a lifting jack of the reversing type which is conveniently and easily operated. 1

Further objects, novel features of construction and improved results will appear in the 15 following detailed description and accompanying drawings. a

In the accompanying drawings:

Figure 1 is a side view of the jack.

Fig. 2 is a front view of the aclr'.

Fig. 3 is an enlarged detail view of the reversing mechanism, the parts being shown in the position they assume when shifted to a hous1ng24, whlch is adapted for lateral an inoperative position.

Figf l is an enlarged detail view of the reversing mechanism, the parts being shown moved into their operative position for effecting a reversal or lowering of the jack.

Fig. 5 illustrates a modified form of the invention and is a fragmentary view of the 30 invention applied to a power jack.

Referring now to the drawings in detail,

5 indicates a standard having a base 6 and a lifting bar as designated at 7, being pror vided with a ratchet 8 carrying on its upper end a head 9. The lifting bar is adapted for reciprocation in the standard 5, which is a common construction found in jacks.

An operating member 10 is pivotally the pawl in engagement with the rack 8 of H the lifting bar. Inthe constructionshown, the ends ofthe coil spring are held 1n posltion by reason of the extending lugs 17 on the mounted as at 11 in the standard and is pro- 1927. Serial No. 186,686.

pawl 13, and the inner face of the standard front portion 16. By reference to Fig. 3 of the drawings, it will be seen that the lower end of the lifting pawl 13 is rounded at 18 to provide a pivotal connection between the ]pawl and the head 14 ofthe operating mem- The check pawl is designated as at 19 and is pivotally supported in the standard 5, as at 20. A coil spring 21, similar in construction to the previously described spring 15, is interposed between the standard front portion 22 and the pawl and tends at all times to hold the pawl in engagement with the rack of the lifting bar. Lugs 23 are used to retain the spring in position between the pawl and the standard front. n

The structure thus far described is sulficient to elevate the bar, but not sufficient-to accomplish a reversal movement to lower the lifting bar.

The reversing mechanism is carried within movement between the guides 25 and 26 carricd onthe side of the standard 5. Movement of the housing and the reversing mechanism is had through the reverse control member 27, the lower end of which is. provided with a handle 28. By reference to Fig. 2 of the drawings, it will be seen that the reverse control member passes through both the upper and lower guides 25 and 26 and parallels the housing 24 containing the reversing mechanism. The reverse controlling member is provided adjacent its upperand lower ends with angularly disposed slots 29 into which extend pins 30 carried by the. reversing mechanism housing.

From the foregoing it will be seen that by pulling downwardly on the handle 28 of the reverse control member, the housing 24 containing the reversing mechanism will be moved between the guides towards the lifting bar operating member 10. To return the housing to its original position, it is only necessary to push upwardly on the handle 28 of the reverse control member. To insure that the reverse controlling member will remain in any set position, a tension member '31 is provided for engagement with the exerts a very considerable amount of friction contact and is sui'ficient to hold the reverse control member in any set position.

Coming now to the reversing mechanism, which is illustrated in enlarged views in Figures 3 and 4 of the drawings, it will be seen that there is'provided a U-shaped carrier 35, to which is rigidly secured, as at 36, a

forwardly or outwardly extending member 37. The member 37 is pivotally supported in the housing at its rear, as at 38. A bow spring 39 is secured to the rear wall 40 of t e housing by suitable carrying means 41 and the ends of the spring are bowed out wardly, as at 42, for engagement with the ends of the U-shaped carrier.

Positioned within the carrier 35, above the member 37, is a block 43 and below the carrier a second block 44. These blocks are provided with shoulders 45 adapted to engage the external shoulders 46 of the member 37. The blocks 43 and 44 are retained in the carrier under spring tension. This tension is provided through the medium of coil springs 47 interposed between the carrier and the blocks. The blocks are provided with a bore 48 adapted to receive the ends of the springs. The bottom of the bores are provided with an up-struck lug 49 to hold the spring in position, while the ends of the spring engaging the carrier are held in position by reason of the lugs 50. It will be readily apparent that the blocks cannot escape from the carrier as their shoulders engage the shoulders of the member 37.

The outer end or face of the member 37 is cut out to form a U-shaped groove or seat 51. The upper ends of this groove are provided with a rounded taper 52, which in turn terminates at the front edge of the member in a more deeply cut arc-shaped portion 53.

The head 14 of the lifting bar operating mechanism 10 carries an extending camshaped arm 54, which is adapted for engagement with the groove in the reversing mechanism member 37. The lifting and check pawls are provided with extending pins 55, which are adapted tocbe engaged by the spring mounted blocks 43 and 44 of the reversing mechanism.

- It will be understood that most of the lifting and lowering work is done by the head 9 of the lifting bar, but I have, however, provided. adjacent the lower end of the lifting bar an outwardly extending workengaging arm 56.

Having described the'component parts of the jack and its reversing mechanism, a short description of the operation will now be given.

Operation Lifting operation-From the description of the parts given above, the lifting operation should be readily understood. When the lifting operation takes place, the reversing mechanism is in the positions shown in Figures 1 and 3 of the drawings.

By oscillating the operating handle 10, through the medium of the extension handle 12, the lifting bar is raised one tooth at the time to each full stroke of the operating handle and the lifting pawl 13, having engagement with one of the teeth of the rack, raises the lifting bar one tooth and the lifting bar is held in place by the check pawl 19, while the lifting pawl is being again lowered to repeat its lifting operation.

It will be seen throughout the lifting oper-' ation that the cam-shaped arm 54 of the operating member 10, does not engage the member 37 of the reversing mechanism, but that this arm oscillates in an are parallel to, but slightly separated from the are of the arc-shaped portions 53 at the extreme outer end of the groove 51.

Lowering 0pemtz'0n.VVhen the lifting bar has been elevated and it is desired to lower the same, the reversing mechanism is moved into the position shown in Figure 3 of the drawings by pulling downwardly on the handle of the reverse operating lever 27.

It will now be seen that when the operating member 10 is oscillated, its cam-shaped arm 54 will alternately engage the beveled portions 52 of the U-shaped groove 51, and that through this engagement the member 37 and its carrier 35 will be rocked upon the pivotal support 38. The rocking of the member 37 and the carrier will, of course be against the tension of the bow-spring 42.

As the reversing mechanism carrier and its component parts are rocked the blocks 43 and 44 are alternately brought into engagement with the pins 55 of the lifting and check pawls, thus alternately. disengaging these pawls from the rack of the lifting bar.

Alternate disengagement of the lifting and check pawls permits the lifting bar to lower one tooth at a time. It will be seen that the oscillation of the operating lever need not be very great to cause the pawls to be alternate- 1y actuated by the reversing mechanism, as the reversing mechanism slides towards the operating lever to a point where the blocks 43 and 44 are actually adjusting the pawl pins while the cam-shaped arm of the operating lever is in the deep U-shaped groove of the member 37 Thus a very slight oscillation of the operating lever causes its cam-like arm to alternately engage the beveledportions 52, and thus rockthe reversingmechanism, i

It will be obvious that during the lowering operation when the blocks 43 and 44 are: brought alternately into engagement with the pins 55 of the pawls 13 and19, should these pawls still be under pressure of a load carried" by the rack, the springs 47 and 48* of these.

rack.

Attention is directed to the arc-shaped por: tion 53' of the member 37 and it is pointed out that this portion is so shaped for two reasons. The primary reason is that during the move,-

a merit of the operating levenldduring the lifting operation the cam-shaped arm 54 moves freely and does not engage the member 37. The secondary reason is that this arc-1 shaped portion guides the cam arm 54 into.

the groove 51 of the member 37' when the re-.

verse lever 28 is pulled downwardly and the reversing mechanism moved outwardly to? ward the operating handle.

In the drawings, the U-shaped carrier is shown asan independent piece,v bolted or 1 otherwise. suitably secured to the. member 37L t as It will, however, be obvious that should it be desirable, thecarrier 35 can be eliminated and the member 37 formed of a single piece to in: elude the brackets in which the'blocks reciprocate. a 7

he bow. spring before mentioned and bearing the numeral 39, might be termed a balancing spring as it holds member 37 of the reversing mechanism in a straight position so that the cam armsi will be guided into thegroove 51 when the reversing mechanism is moved toward the operating lever by pulling downwardly on the reverse control handle 28, a p

"Modified form of the z'mzcottz'on. -By reference to Figure 5 it will be'seen that the invention is equally applicable to a power oper ated jack.

Here the jack is of similar construction to the jack previously described, with the exception of the enlarged housing 100 in which is mounted the large gear wheel 101 and the .smaller' gear 102. It will be seen that the pawls 13 and 19 engage the large gear and a cause it to rotate and that this gear in turn causes the rotation of the smaller gear as theyare both, secured to a; common shaft 103,.

cordance to whether or not it is desired to lift or lower the load.

In this modified form of the invention the reversing mechanism is identical to that pre-. viously described, and operated in exactly the same manner. t

Having thus described my invention, what I desire to claim and secure by Letters Pat: ent. of the United States is t 1. A jack comprising a standard, a rack slidably mounted therein, a lifting pawl and a check pawl, an actuating; lever: mounted on said jack, said lever having an enlarged head operatively connected with said lifting pawl, a reversing mechanism sl-idably mounted on said standard, means for sliding said mechanism into andout of engagement withthe: head of said actuating lever, saidreversing mechanism its extended position mounted for alternate engagement with said pawls, and said reversing mechanism when in its extended position actuated by said operating lever for alternately engaging the pawls, for the purpose described.

2. A jack comprising a standard,v a rack slidably mounted therein, a lifting pawl and a check pawl in engagement with said rack, an actuating lever operatively connected with the lifting pawl, a reversing mechanism comprising a rocking member adaptedto al-. ternately actuate said pawls, and said reversing mechanism movably mounted on said jack for operative engagement with the actuating lever to be rocked by said lever. V

3. A jack comprising a standard, a rack slidably mounted therein, a lifting pawl and a check pawl,.an actuating leverafor said lifting pawl operatively connected with said lifting pawl, a reversing mechanism compris-. ing a rocking member, said reversing mechas nism movable for engagement with the actuating lever to be rocked thereby, a secondary! means carried by the said rocking member for alternate engagement with the pawls for! alternately check pawls, and said pivotallymounted part of the reversing mechanism rocked upon its pivotal support by said oscillating actuat ing lever. t a i t t o 5. A jack comprising a standard, a rackslidably mounted therein, ,alifti 'g pawl and a check pawl both pivotally mounted in respect to said rack and said check pawl in constant engagement with the rackduring' the lifting thereof, an actuating lever pivotally mounted on said standard and in operative engagement with the lifting pawl, and a re versing mechanism pivotally and slidably mounted in respect to the standard, means to move the reversing mechanism into engagement with the actuating lever, means for operative engagement between the reversing mechanism and thepawls, whereby upon the actuation of the reversing mechanism by the actuating lever the pawls are alternately dis-- engaged from the lifting rack.

6. A jack comprising a standard, a rack slidably mounted therein, a lifting pawl and a check pawl, an actuating lever pivotally mounted on said standard and in operative engagement with said lifting pawl, a reversing mechanism pivotally and slidably mountedin respect to the standard, said reversing mechanism adapted 'to be rocked on its pivot by said actuating lever, a resilient member behind said rocking mechanism to cause the rocking mechanism to be rocked against resilient tension, and a pair of members resiliently mounted in said reversing mechanism, said resilient members adapted to alternately engage and actuate the pawls when {he reversing member rocks by the actuating ever.

7. A jack comprising a standard, a rack slidable therein, a lifting pawl and a check pawl therefor, an operating lever pivotally mounted on the standard and operatively connected with said lifting pawl, a reversing mechanism slidably mounted on the standard for operative engagement with said operating lever, said reversing mechanism being pivotally mounted in respect to the standard, a cam-like groove in said reversing mechanism, a cam-like member carried by the operating lever for engagement with said groove to rock the reversing mechanism upon its pivotal support and the ends of said reversing mechanism adapted to alternately engage said pawls when said reversing mechanism is rocked by the operating lever, for the purpose described. 1

8. A jack comprising a standard, a rack slidably mounted therein, a lifting pawl and a check pawl both being pivotally mounted in respect to said rack, resilient means for holding said pawls in engagement with said rack, an operating lever pivotally mounted on said standard and operatively connected with the lifting pawl for actuating the same, a reversing mechanism movably mounted on said standardfor engagement with said operating lever, said reversing mechanismcomprising a member pivotally mounted in respect to the standard and provided with blocks in its ends movably mounted in saidmember against resilient tension, said blocks adapted for alternate engagement with saidpawls, a resilient member positioned behind the pivotally mounted member for the purpose of returning the same to its normal position after said member has been rocked by the operating lever, and the operating lever through its on gageinent with said pivotally mounted member adapted to rock said member to cause the resiliently mounted blocks thereof to alternately engage the pawls and alternately force them out of engagement with the rack.

9. A jack comprising a standard, a rack slidably mounted therein, a check pawl and a lifting pawl pivotally mounted in respect to said rack, an actuating lever pivotally mounted on the standard provided with a head, said lever operatively connected with said lifting pawl, a reversing mechanism pivotally mounted on said standard and adapted to al ternately engage said pawls for alternately forcing them out of engagement with said rack for causing the lowering of said rack, and the head of said actuating lever in operative engagement with said reversing mechanism for rocking the same upon its pivotal connection, for the purpose specified.

, 10. A jack comprising a standard, a rack slidably mounted therein, a check pawl and a lifting pawl pivotally mounted in respect to the rack, an actuating lever pivotally mounted on the standard and operatively connected with the lifting pawl, said lever provided with an enlarged head, areversing mechanism pivotally and slidably mounted on and in respect to the standard, means to slide the reversing mechanism into engagement with the head of said lever, whereby said lever rocks said reversing mechanism upon its pivotal mounting to cause said mechanism to alternately disengage the pawls from the rack, for the purpose described.

11. A jack comprising a standard, a rack slidably mounted therein, a lifting pawl and a check pawl pivotally mounted in respect to said rack, an actuating lever pivotally mounted on the standard and in operative engagement with said lifting pawl, a reversing mechanism pivotally and slidably mounted on and in respect to the standard for permitting the reversing mechanism to be slid into engagement with and be rocked on its pivot by said actuating lever, and resiliently mounted members carried by said reversing mechanism for alternately engaging and actuating the pawls when the reversing mechanism is rocked by the operating lever, for the purpose described,

12. A jack comprising a standard, a rack slidably mounted therein, a lifting pawl and a check pawl pivotally supported in respect to the rack, means for holding said pawls in engagement with the rack, an operating lever pivotally supported onsaid standard and operatively connected with the lifting pawl to actuate the same, a reversing mechanism movably mounted on and in respect to said standard for engagement with the operating lever, said reversing mechanism including a member pivotally mounted in respect to the standard and carrying resiliently mounted blocks adapted for alternate engagement with the pawls, the operating lever through its engagement with said pivotally mounted ,member adapted to rock the same to cause the resiliently mounted blocks thereof to alternately engage the pawls and alternately move them out of engagement with the rack, and means to return the pivotally mounted member of the reversing mechanism to its normal or neutral position after the same has been rocked in either direction.

13. A jack comprising a standard, a rack slidably mounted therein, a lifting pawl and a check pawl pivotally mounted in respect to the rack and in engagement with said rack, an actuating lever pivoted on said standard and having operative connection with the lifting pawl, a reversing mechanism slidably mounted upon the side of said standard including a member pivotally mounted in respect to the. standard, said mechanism adapted to he slid into engagement with the actuating lever to permit the pivotally mounted memberthereof tobe rocked thereby, said pivotally mounted member when rocked alternately striking and forcing said pawls out of engagement with said rack, and a vertically movable manually operated control member for sliding the reversing mechanism into and out of engagement with the actuating lever, for the purpose described.

In testimony whereof I hereunto afiix my signature.

WILLIAM H. STONE. 

